Hood for attachment to diamond tools



Sept. 2, 1941. pg-jg v I 2,254,393

HOOD FOR ATTACHMENT T0 DIAMOND TOOLS Filed D90. 24, 19 40 E i-i5:

c/omv L. Pepe/s. v Mfifi Patented Sept. 2, 1941 John L. Petric, Detroit, Mich, assignor to Wheel Trueing Tool Company of Delaware, Detroit,

Mich, a corporation of Delaware Application December 24, 1940, Serial No. 371,469

Claims.

This invention relates to a hood attachment for diamond dressing tools. 7

Heat is generated at the diamond point of a dressing tool applied to the face of a. rotatin grinding wheel. Since it is known that this heat.

affects the diamond pointed tool adversely, many conventional dressing devices comprise means for emitting a jet of cooling water against the face of thewheel being dressed immediately ahead of the point of application of the tool. However, the water flowing against the face of the fast turning wheel tends to splash and also to rebound from the dressing tool in a manner that does not permit the water actually to contact and cool 'the diamond point. In some devices the water is prevented from reaching the diamond point by the centrifugal force of the rotating wheel which may throw the water away from the face of the wheel. 'The cooling devices ends ofthe legs, the water tends to fill the hood and to swirl around therein, thus cooling the diamond effectively.

Hoods according to this invention are particularly well adapted for us in condunction with the Diamond dressing too disclosed in my pending application, Serial No. 349,513, filed August 2, 1940. It is therefore an important object of the present invention to provide means for guiding a stream of coolant into constant .intimate contact with the diamond point of a dressing tool applied to the face of a rotating grinding wheel. A more specific object of the invention is to provide a hood attached to a diamond pointed dressing tool for grinding wheels which comprises the diamond point whose leading ends form projecting wings and whose trailing ends are deflected toward each other into closely spaced relationship;

Other and-further important-objects of this invention will become apparent from the specification and appended claims.

' paired spaced shields disposable on each side of 7 shown in Figure 7. v

This invention (in a preferred form) is illustrated in the drawing and hereinafter more fully described.

On the drawing:

Figure 1 is a fragmentary end eievational view,

with parts in cross section, of a grinding wheel and a diamond pointed dressing tool with an attached hood according to this invention and a water jet, as assembled for an external dressing operation.

Figure 2 is a fragmentary endelevational view, with parts in cross section of'a grinding 'wheel and a diamond pointed dressing tool with an attached hood according to this invention and a water jet as assembled for a dressing operation on a centerless grinder.

Figure 3 is a side elevational view with parts broken away and in section, of a dressing tool having diamonds arranged in tiers inwardly of the end thereof as disclosed in my application, Serial No. 349,513 and a hood according to the present invention attached to said tool.

Figure 4 is a front elevation of the assembly shown in Figure 3.

Figure 5 is a bottom plan view of the assembly shown in Figure 3.

Figure 6 is a side elevational view with parts broken away and in section, of a dressing tool similar to the tool shown in,Figure 3v together with a hood according to this invention attached to the tool in adiiferent manner.

Figure '7 is a side elevational view, with parts broken away and in section, of a dressingtool similar to the tool shown in Figure 3 together with a hood according to this invention attached to the tool in still another manner.

, Figure 8 isa bottom plan view of the assembly shown in Figure 7.

Figure 9 is a transverse cross-sectional view along the line IX-IX through the assembly Similar parts in the various figures are indicated by like numerals. As shown on the drawing:

In Figure 1, there is shown an assembly including a grinding wheel l0. Means, not shown, hold the wheel Ill for rotation during the grinding operation in the direction of the arrow. A tool holder It serves to hold a diamond pointed tool I! in external dressing relationship to the surface of the grinding wheel I0. A pipe 13 jets water onto the surface of the grinding wheel l0 ahead of the point of application of the tool 12. The streaming water jetted onto the'wheel by 2 4 the pipe I: a guided into close contact with the pointofthedressingtoolbyahood l4.

lnFigureathereisshownanassemblyincluding a grinding wheel II and a mounting indicated generally by'the reference numeral II for holding the grinding wheel I I for rotation wheel ll ahead of the point of application of the tool l2. The streaming water jetted onto the wheel by the pipe Ila is guided into close contactwiththepointofthedressingtoolbya hood I As shown in Figures 3 to 5, the tool [2 comprises a cylindrical shank 24 from which extends an offset end 2| of reduced thickness. Tapering shoulders 22 extend laterally from the upper terminus'of the end" 2!; The end 2| has a rectangularly flat end face or bottom 23. The metal of the tool end 2| comprises a matrix in which are embedded a plurality of diamonds 24 some of which project from the end face 23.

The hood i 4 includes'an upper hollow tubular portion or shank ll seated around the lower end of the tool shank 2| and aflixed thereto by spot welds 2!. A lower U-shaped portion has a lower' edge 32 which extends in parallelism with the tool end face 23, l. e., with its trailing bridging end portion or bight projecting further from the tubular portion 30 than its leading free leg ends.

to conform roughly to the form of the wheel to be dressed. This lower U-shaped portion comprises a seml-circularsegment 23 slotted axially at 84 joining projecting wings 2'.

Figure 6 shows a dressing tool hood assembly similar to that shown in Figures 3 to except that the hood is attached to the shank of the dressing tool by means of a terminally upset pin 4| piercing the shank 20 and the'tubular hood portion ll instead of by means of spot welding.

Figures 7 to 9 show a dressing tool hood assembly in which the tool, h e Benerally similar to those shown in Figures 3 to 6, is characterized by a circumferential groove 4| around the lower end portion of the tool shank 2.. The tool end 2ia is a constricted axial prolongation beyond a circumferential shoulder 22!: of the tool shank 2| and termlnatesin a rounded end face- 224. The

hood made from spring-hardened steel is formed a speed of about one mile per minute is caught by i the wings of the hood and directed around the point of the tool to cool the same. Grit cut from the face of the wheel is washed out through the slot in the hood.

The hood is brought into engagement with the wheel during the dressing operation and is worn down at the same rate as the tool end. Thus the hood soon conforms with the exact contour of the wheel being dressed;

Hoods for dressing tools according to this invention are not limited to the illustrative examples described hereinabove but include broadly any and all means associated with pointed dress- ,ing tools for collecting coolant on the face of a -life of diamond pointed dressing tools far beyond what prior art workers have thought possible.

Since many details of construction may be varied within a wid range without departing from the principles of this invention, it is not my purpose to limit the patent granted on this invention otherwise than necessitated by the scope of the appended claims.

I claim:

l. A hood for a diamond pointed dressing tool including a shank and a constricted pointed end portion, said hood comprising a tubular portion adapted to be seated on said shank and a U- shaped shield portion with wing-like legs projecting ahead of the end portion of said pointed tool and a longitudinally slotted bight portion adapted to trail said pointed tool end.

2. A hood for a diamond pointed tool for dressing the face of a grinding wheel including a shank and a constricted pointed end portion, said hood comprising a tubular portion adapted to be seated on said shank and a U-shaped shield having legs forming wings adapted toproject ahead of said pointed tool end portion and a longitudinally slotted bight adapted to trail said pointed tool end, the terminal edge of said shield receding from the trailing to the leading ends thereof to conform to the shape of said wheel.

. 3. A hooded diamond pointed tool for dressing the face of a grinding wheel comprising a shank, a constricted pointed end portion, a tubular segment seated on andwelded onto saidshank and a U-shaped shield integral with said tubular segment having. a longitudinally slotted" trailing bight and leading leg portions. Y

4. A hooded diamond pointed tool for dressing the face of a grinding wheel comprising a shank, a constricted pointed end portion, a tubular segment seated on said shank, a terminally upset pin piercing said shank and said tubular segment, and a U-shaped shield integral with said tubular segment having a longitudinally slotted trailing bight and leading leg portions.

5. A hooded diamond pointed tool for dressing the face of a grinding wheel comprising a shank having a circumferential groove, a constricted pointed end portion, a tubular segment having a plurality of indentations seated on said shank with said indentations seated in said groove, and a u-fllllaped shield integral with said tubular segmen aving a longitudinally slotted tra and leading leg portions. mm his? 6. A hood for a diamond pointed dressing tool comprising a tubular member having two op- Posed axlal slots opening at, on nd of i her and two partially circumferential slots communicating with the inner end of one of said axial slots, those segments of said tubular memher intermediate said circumferential slots and having a diamond-carrying end portion adapted.

the terminal edge at which said axial slots open being straightened to form projecting wings.

7. In combination with a wheel dressing tool adapted to be cooled by a stream of coolant, a hood carried by the tool having a coolant-directing wall spaced outwardly from the tool and provided with a leading edge adapted to engage a ing from said tubular portion around the dia-- mend-carrying portion of the tool in spaced relation therefrom to provide a chamber around said diamond-carrying portion, and said wall having coolant inlet and outlet passages therein sized for flow of coolant through the chamber while selectively retaining coolant around the diamond-carrying portion or the tool.

9. In combination with a wheel dressing. tool to be cooled by a stream of coolant, paired spaced shields disposed on opposite sides of the tool and extending in spaced relation 11m he diamond-carrying portion of the tool to provide a chamber around said portion, said shielos having leading ends spaced farther apart than their trailing ends to provide inlet and outlet passageways to the chamber whereby coolant can flow through the chamber while being selectively retained therein to contact the diamond-carrying portion of the tool.

10. In a wheel dressing assembly including a dressing tool having a diamond-carrying end portion, a wheel adapted to be dressed by said tool, and means for flowing a stream of coolant adjacent the tool, the improvement which comprises a hood carried by the tool with a portion disposed around the diamond-carrying portion of the tool havingv a leading edge engaging the wheel to provide a chamber around said diamond-carrying portion-of the tool receiving coolant from said stream to selectively retain the coolant in 'contact with said diamond-carrying portion for cooling the diamonds.

JOHN L. PETRIE. 

